curds: Keep a map of PlaylistNode ids

Making it easy to look up a PlaylistNode by the python object id means
we can use the object id in the GtkTreeIter rather than storing the
entire path

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

curds/playlist/node.py

@@ -1,6 +1,8 @@
 # Copyright 2019 (c) Anna Schumaker.
 from .. import notify
 
+nodes = dict()
+
 class PlaylistNode:
     def __init__(self, name="", icon=""):
         self.children   = [ ]
@@ -9,6 +11,7 @@ class PlaylistNode:
         self.next_child = None
         self.parent     = None
         self.prev_child = None
+        nodes[id(self)] = self
 
     def __link_children__(self, a, b, c):
         if a != None:
@@ -73,6 +76,12 @@ class PlaylistNode:
                 return node
         return None
 
+    def lookup_byid(self, id):
+        node = nodes.get(id)
+        if node == None or node.get_root() != self.get_root():
+            return None
+        return node
+
     def n_children(self):
         return len(self.children)
 
@@ -87,4 +96,6 @@ class PlaylistNode:
         return None
 
     def reset(self):
+        for child in self.children:
+            del nodes[id(child)]
         self.children.clear()

curds/playlist/test_node.py

@@ -4,21 +4,28 @@ from .. import notify
 import unittest
 
 class TestPlaylistNode(unittest.TestCase):
+    def setUp(self):
+        node.nodes.clear()
+
     def on_insert_node(self, node, index):
         self.cb_insert = (node, index)
 
     def test_node_init(self):
+        self.assertIsInstance(node.nodes, dict)
+
         n = node.PlaylistNode()
         self.assertEqual( n.children, [ ])
         self.assertEqual( n.icon, "")
         self.assertEqual( n.name, "")
         self.assertIsNone(n.next_child)
         self.assertIsNone(n.prev_child)
+        self.assertEqual(node.nodes.get(id(n)), n)
 
         n = node.PlaylistNode("test node", "test-icon")
         self.assertEqual(n.icon, "test-icon")
         self.assertEqual(n.name, "Test Node")
         self.assertEqual(str(n), "<big>Test Node</big>")
+        self.assertEqual(node.nodes.get(id(n)), n)
 
     def test_node_less_than(self):
         a = node.PlaylistNode("a")
@@ -119,6 +126,7 @@ class TestPlaylistNode(unittest.TestCase):
         root = node.PlaylistNode()
         a = node.PlaylistNode("a")
         b = node.PlaylistNode("b")
+        c = node.PlaylistNode("c")
 
         root.append_child(a)
         root.append_child(b)
@@ -127,6 +135,11 @@ class TestPlaylistNode(unittest.TestCase):
         self.assertEqual( root.lookup("b"), b)
         self.assertIsNone(root.lookup("c"))
 
+        self.assertEqual( root.lookup_byid(id(a)), a)
+        self.assertEqual( root.lookup_byid(id(b)), b)
+        self.assertIsNone(root.lookup_byid(id(c)))
+        self.assertIsNone(root.lookup_byid(42))
+
     def test_node_nth_child(self):
         root = node.PlaylistNode()
         a = node.PlaylistNode("a")
@@ -236,3 +249,4 @@ class TestPlaylistNode(unittest.TestCase):
 
         root.reset()
         self.assertEqual(root.children, [ ])
+        self.assertEqual(node.nodes, { id(root) : root })